[PATCH 01/10] USB: OHCI: Properly handle ohci-at91 suspend

[Alan Stern]

On Wed, 12 Jun 2013, Alan Stern wrote:

> On Wed, 12 Jun 2013, Manjunath Goudar wrote:
> 
> > Suspend scenario in case of ohci-at91 glue was not properly
> > handled as it was not suspending generic part of ohci controller.
> > Calling explicitly the ohci_suspend()routine in ohci_hcd_at91_drv_suspend()
> > will ensure proper handling of suspend scenario.
> 
> > diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c
> > index fb2f127..28400a7 100644
> > --- a/drivers/usb/host/ohci-at91.c
> > +++ b/drivers/usb/host/ohci-at91.c
> > @@ -619,8 +619,12 @@ ohci_hcd_at91_drv_suspend(struct platform_device *pdev, pm_message_t mesg)
> >  {
> >  	struct usb_hcd	*hcd = platform_get_drvdata(pdev);
> >  	struct ohci_hcd	*ohci = hcd_to_ohci(hcd);
> > +	bool do_wakeup = device_may_wakeup(&pdev->dev);
> > +	int ret;
> >  
> > -	if (device_may_wakeup(&pdev->dev))
> > +	ret = ohci_suspend(hcd, do_wakeup);
> > +
> > +	if (do_wakeup)
> >  		enable_irq_wake(hcd->irq);
> >  
> >  	/*
> > @@ -637,7 +641,7 @@ ohci_hcd_at91_drv_suspend(struct platform_device *pdev, pm_message_t mesg)
> >  		at91_stop_clock();
> >  	}
> >  
> > -	return 0;
> > +	return ret;
> 
> If ohci_suspend() fails, we should return right away.  Don't execute 
> the enable_irq_wake() and all the other stuff.

Actually, the situation is more complicated.  In order to handle races
with remote wakeup, the logic we need is more like this:


Index: usb-3.10/drivers/usb/host/ohci-at91.c
===================================================================
--- usb-3.10.orig/drivers/usb/host/ohci-at91.c
+++ usb-3.10/drivers/usb/host/ohci-at91.c
@@ -674,8 +674,18 @@ ohci_hcd_at91_drv_suspend(struct platfor
 {
 	struct usb_hcd	*hcd = platform_get_drvdata(pdev);
 	struct ohci_hcd	*ohci = hcd_to_ohci(hcd);
+	bool		do_wakeup = device_may_wakeup(&pdev->dev);
+	int		ret;
 
-	if (device_may_wakeup(&pdev->dev))
+	ret = ohci_suspend(hcd, do_wakeup);
+	if (ret == 0 && do_wakeup && HCD_WAKEUP_PENDING(hcd)) {
+		ohci_resume(hcd, false);
+		ret = -EBUSY;
+	}
+	if (ret)
+		return ret;
+
+	if (do_wakeup)
 		enable_irq_wake(hcd->irq);
 
 	/*
@@ -692,7 +702,7 @@ ohci_hcd_at91_drv_suspend(struct platfor
 		at91_stop_clock();
 	}
 
-	return 0;
+	return ret;
 }
 
 static int ohci_hcd_at91_drv_resume(struct platform_device *pdev)

The same is true for all the other drivers.

Alan Stern